US developer Power to Hydrogen (P2H2) and Spanish energy company Repsol have jointly announced the successful completion of a pilot test of P2H2's hybrid AEM electrolysis technology. The test took place at Repsol's All4Zero industrial innovation hub. According to the companies, the system met or exceeded key performance targets in efficiency, flexibility and durability. Both partners see the results as evidence that AEM electrolysis can be a lower-cost pathway to renewable hydrogen at industrial scale.
Projected hydrogen costs of 3.86 euros per kilogram
Using inputs provided by Repsol and the U.S. Department of Energy's H2A-Lite analysis framework, P2H2 projects a levelized cost of hydrogen of around 3.86 euros per kilogram. According to the company, this represents a reduction of approximately 16 percent compared with incumbent electrolyzer technologies. Under optimised renewable energy scenarios with hybrid power purchase agreements, the cost could fall to around 2.82 euros per kilogram, P2H2 states.
"This pilot proves what we've long believed: that AEM electrolysis can deliver PEM-like performance at a fundamentally lower cost structure," said Paul Matter, founder and CEO of Power to Hydrogen. "With Repsol's rigorous testing framework and real-world operating conditions, we've demonstrated the durability and efficiency that the market has been waiting to see from AEM."
1,250 hours of testing, expected lifetime of more than 50,000 hours
The test protocol at All4Zero included variable load profiles based on real operating conditions, repeated cycling between 40 and 100 percent load, and operation across pressures from 2 to 30 bar. According to P2H2, the stack showed only around 2 millivolts per 1,000 hours of irreversible degradation over the 1,250 hours of testing. The average cell voltage remained virtually unchanged between the start and end of the test. Based on these results, P2H2 projects system lifetimes of more than 50,000 hours. This would exceed current AEM industry benchmarks by a factor of five to ten, the company states.
Hydrogen purity directly from the stack reached up to 99.9 percent at an operating pressure of 30 bar, with consistent performance across the full pressure range from 2 to 30 bar. The system also demonstrated dynamic load response and remained fully resilient through unplanned shutdowns, including a facility power outage. After the outage, testing resumed without consequence, according to the companies.
P2H2 highlights that its technology uses an iridium-free and PFAS-free materials pathway. From the developer's perspective, this reduces dependencies on critical minerals and mitigates regulatory risks associated with conventional PEM electrolysis.
Next step: demonstration in the megawatt range in Netherlands and Norway
Based on the pilot results, P2H2 and Repsol are exploring pathways to a larger demonstration at the 500 kilowatt to megawatt level. This is intended to support Repsol's target of installing 600 to 800 megawatts of renewable hydrogen capacity by 2030. P2H2 states it is already deploying systems at this scale, including ongoing projects at the Port of Antwerp-Bruges and with the Norwegian research organisation SINTEF.
"Through our All4Zero accelerator, Repsol is committed to identifying and validating the technologies that will be essential to decarbonizing industrial operations at scale," said Berta Moreno, senior scientist at Repsol. "Power to Hydrogen's results demonstrate meaningful progress toward the performance thresholds required for large-scale renewable hydrogen deployment."
Power to Hydrogen, based in Columbus, Ohio, develops electrolyzer systems based on anion exchange membrane technology. According to the company, its platform is designed for sub-50-millisecond load response and high-pressure hydrogen output, and is engineered for direct integration with variable renewable power.
